A semiconductor apparatus that drives an inductive load (transformer coil) of, for example, an ignition system for an internal combustion engine uses the mutual inductive effects of the transformer coil to cause a spark discharge of several tens kV at a spark plug connected to the secondary side of the transformer coil to cause ignition. The apparatus is therefore required to have a surge withstand capacity of several to several tens kV because unexpected surges occur irregularly at a high-voltage terminal.
Techniques developed for the purpose of reducing the apparatus size and increasing the functionality of semiconductor apparatuses for internal combustion applications have been known, wherein a power semiconductor device and a backside high withstand voltage integrated circuit that controls the former are mounted on one conductor plate with a conductive bonding material (see, for example, PTL 1).